# NTSB ERA11LA297: Bell 206-L4, N266P, Mobile Block 114CC, May 13, 2011 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: May 13, 2011, 11:20 local (16:20 UTC) - Place: Mobile Block 114CC - Coordinates: 30.191667, -88.025001 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=30.1917&lon=-88.0250&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of tail rotor effectiveness](https://openairdocs.org/ntsb-events/242) - Highest injury: Serious injuries - Injuries: 2 serious, 1 uninjured - Status: Completed, report February 6, 2012 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO, PHI, Inc. - NTSB case key (mKey): 79095 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA11LA297 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/79095/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=79095 - Page: https://openairdocs.org/ntsb/ERA11LA297 ## Probable cause The pilot’s operation of the helicopter with a left, quartering headwind, resulting in conditions conducive to a loss of tail rotor effectiveness. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: yaw control](https://openairdocs.org/ntsb-findings/01062024): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Bell 206-L4, 1 case](https://openairdocs.org/ntsb-findings/01062024/cases.md?model=1182110), [All aircraft, 149 cases](https://openairdocs.org/ntsb-findings/01062024/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Bell 206-L4, 8 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=1182110), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Wind](https://openairdocs.org/ntsb-findings/03034000): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Bell 206-L4, 1 case](https://openairdocs.org/ntsb-findings/03034000/cases.md?model=1182110), [All aircraft, 110 cases](https://openairdocs.org/ntsb-findings/03034000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Loss of tail rotor effectiveness](https://openairdocs.org/ntsb-events/242) (defining event); cases with it: [Bell 206-L4, 1 case](https://openairdocs.org/ntsb-events/242/sequence.md?model=1182110), [All aircraft, 100 cases](https://openairdocs.org/ntsb-events/242/sequence.md) - [Autorotation: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Bell 206-L4, 5 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=1182110), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis Shortly after liftoff from the production platform helideck, the pilot observed that the helicopter began an uncommanded slow yaw to the right. The pilot applied full left pedal, which had no effect. He lowered the collective, rolled the throttle to idle, and deployed the emergency floats. The helicopter impacted the water and rolled over. A postaccident examination of the wreckage did not reveal evidence of a mechanical malfunction or failure. Tail rotor system continuity was confirmed. The pilot reported that, just prior to the loss of directional control, there was a left, quartering headwind. This condition could have put the helicopter in an area of main rotor disc interference with the tail rotor, which could have resulted in a loss of tail rotor effectiveness. ## Factual narrative On May 13, 2011, about 1120 central daylight time, a Bell 206L-4, N266P, landed in the Gulf of Mexico near the Mobile Block 114CC helideck following an in-flight loss of directional control. The helicopter was substantially damaged. The helicopter was registered to and operated by PHI, Inc. under the provisions of 14 Code of Federal Regulations Part 135 as a passenger flight. Visual meteorological conditions prevailed and a company visual flight rules flight plan was filed. The two pilots sustained serious injuries and the passenger was not injured. The flight was originating at the time of the accident. According to the operator, the pilot positioned the helicopter for a west-southwest departure due to prevailing wind conditions. After clearing the edge of the production platform helideck, the helicopter started a slow yaw to the right. The pilot added full left pedal; however, this did not stop the rotation. After 360 degrees of rotation, the rotation quickened, the pilot stated that he "didn't have a tail rotor," and he lowered the collective and rolled the throttle to idle. The pilot deployed the emergency floats, and the helicopter impacted the water slightly nose low and in a right drift. The helicopter rolled over immediately to the right and stayed afloat. The pilot egressed the helicopter through the broken windscreen area, the left seat pilot egressed through the pilot's open door, and the passenger egressed through the left passenger door. The wreckage was recovered to the operator's facilities in Lafayette, Louisiana where an examination of the wreckage was performed on May 18, 2011. An inspector with the Federal Aviation Administration (FAA) provided oversight for the examination, assisted by the operator and an investigator from Bell Helicopter. The examination of the engine, tail rotor gearbox, tail rotor drive shaft, main gear box, and main rotor system did not reveal evidence of a pre-existing mechanical malfunction or anomaly. All long tail rotor drive shaft segments were connected. The tail rotor gear box was manually turned, and drive shaft continuity was verified. There was rotational scoring of the tail boom surface in the area of the tail rotor blades. No unusual noise was noted when the tail rotor gear box was rotated in both directions. The tail rotor pedals moved in both directions and no binding was noted. FAA inspectors conducted an interview with the pilot after the accident. The pilot reported that, immediately prior to the loss of directional control, the winds were coming from the left, front quarter of the helicopter. The FAA inspector reported that this would have put the helicopter in an area of main rotor disc interference with the tail rotor, which could have resulted in a loss of tail rotor effectiveness. ## Aircraft - Registration: [N266P](https://openairdocs.org/deregistered/N266P-2014-09-05), registration cancelled 2014-09-05, S/N 52271, built 2002 (OpenAirDocs) - Reported make and model: BELL 206-L4 - Registry model: [Bell 206-L4](https://openairdocs.org/model/bell-206-l4) (registry code 1182110) (OpenAirDocs) - Registry engine: [Allison 250-C30 series](https://openairdocs.org/engine/allison-250-c30-series) (registry code 03015, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 52271 - Airframe hours: 8870 - Engines: ALLISON 250-C30 SER 650 horsepower turbo shaft - Damage: Substantial damage - Flight: Part 135 - Operator: Phi Inc - Registered owner: Phi Inc - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, May 9, 2011 - Departed: Mobile Block 114CC, GM - Destination: Mobile Block 114CC, GM - Flight plan: Company VFR - Airport: Mobile Block 114CC ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; injuries: serious; commercial, flight instructor; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: helicopter; medical: class 2, with waivers/limitations; last flight review October 29, 2010; seat: right; flight hours: 16,070 total, 7,741 as pilot in command, 69 in the last 90 days, 14 in the last 30 days - Co-pilot; age 22; injuries: serious; flight instructor, commercial; instrument ratings: helicopter; medical: class 2, with waivers/limitations; last flight review February 17, 2011; seat: left; flight hours: 1,778 total, 683 in this make and model, 104 in the last 90 days, 43 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: 20,000 ft overcast - Temperature: 82 °F, dew point 70 °F - Altimeter: 29.88 inHg - Observed at: MOB, 30 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20110513011549A](https://openairdocs.org/incident/20110513011549A), May 13, 2011: Bell 206-L4, Theodore, AL, Substantial damage. The winds were generally from the south, which due to obstructions meant that the departure would necessarily be to either the sw or se. Each departure… ## Docket (8 files) The files NTSB released with the investigation on December 13, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=79095. 2.7 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 820 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353576&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Pilot Written Statements (item 2, .PDF, 192 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353577&FileExtension=.PDF&FileName=Pilot%20Written%20Statements-Redacted.PDF - FAA Statement of Phone Conversation (item 3, .PDF, 148 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353578&FileExtension=.PDF&FileName=FAA%20Statement%20of%20Phone%20Conversation-Redacted.PDF - FAA Inspector Statement (item 4, .PDF, 75 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353579&FileExtension=.PDF&FileName=FAA%20Inspector%20Statement-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 5, .PDF, 194 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353580&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Excerpts - Bell 206L4 Flight Manual (item 6, .PDF, 157 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353581&FileExtension=.PDF&FileName=Excerpts%20-%20Bell%20206L4%20Flight%20Manual-Master.PDF - Photo 1: Tail Rotor Area (FAA Photo) (item 7, .PDF, 526 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353592&FileExtension=.PDF&FileName=Photo%201%3A%20Tail%20Rotor%20Area%20(FAA%20Photo)-Master.PDF - Photo 2: Tail Rotor Area (FAA Photo) (item 8, .PDF, 560 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353594&FileExtension=.PDF&FileName=Photo%202%3A%20Tail%20Rotor%20Area%20(FAA%20Photo)-Master.PDF From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.